The present invention relates to packaging for surgical implants and medical equipment. The present invention also relates to a method of packaging surgical implants and medical equipment.
It is well known to repair damage to bone through the use of surgical implants to replace part or all of the natural bone. For example, surgical reconstruction of a hip joint may require a femoral implant to be implanted at the end of the femur and an acetabular cup implant positioned within a reamed acetabular cavity or the natural acetabulum to receive the prosthetic bearing head.
It is known to provide a coating, which promotes osseointegration, to a surface of an implant that contacts the bone. Osseointegration is the direct structural and functional connection between living bone and the surface of an implant. Osseointegration may result from bioactive retention whereby the implant is coated with a bioactive material which stimulates bone formation leading to a chemical bond in which the implant is ankylosed with the bone. A suitable bioactive coating material is hydroxyapatite (HA, also known as hydroxylapatite). Hydroxyapatite is a naturally occurring mineral font of calcium apatite which forms up to seventy percent of natural bone. A hydroxyapatite coating stimulates bone formation.
Osseointegration may also result from mechanical retention whereby bone ingrowth into surface features of a prosthesis, secures the prosthesis to the bone. A suitable coating comprises a porous layer on a metallic substrate such that bone ingrowth into the pores forms a firm bond between the prosthesis and the bone. There is no chemical retention of the prosthesis and the retention is dependent upon the surface area of the prosthesis. The porous coating may consist of a plurality of small discrete particles of a metallic material bonded together at their points of contact to define a plurality of connected interstitial pores in the coating. Such a coating material, and a method of forming the coating, is described in U.S. Pat. No. 3,855,638. Such a porous coating is commercially available from DePuy Orthopaedics, Inc under the name Porocoat.
Implant coatings may be relatively delicate and susceptible to damage during handling prior to implantation. It is desirable to try to limit the amount of damage by limiting contact with the implant prior to delivery to the surgeon in the operating theatre. It is common practice to provide surgical implants in packages which are sealed by the manufacturer and only opened within the operating theatre. This also ensures that the implant remains sterile.
One known approach to packaging implants is to seal the implant within a first bag, and then place the whole bag in a second sealed bag to provide two sterile barriers. However, this causes the implant to contact the packaging, which risks damage to coatings on the implant. Additionally, when opening the package there is a risk that the implant may be dropped. For double bagged implants it can be difficult to read part numbers or other information printed upon the implants, without opening the package and breaching sterility. Additionally, the packaging may be relatively weak and susceptible to accidental damage.
It is known to provide packaging for products in which a first layer defines recesses to receive the product sealed with a web of material such as a layer of paper, cardboard, aluminium foil or plastic such that the products are trapped between the two layers. Such a package is called a blister pack. The first layer is made from a web of material which can be shaped to form the recesses, usually a thermoformed plastic. The plastic may be a thermoplastic polymer such as polyethylene terephthalate (PET), and in particular PETG which is a clear thermoplastic that can be injection moulded and is commonly used in food packaging. A suitable material for the second layer is Tyvek® which is a tear resistant clear plastic film.
It is known to use blister packs to package implants, however unless additional structures are built into the blister packs then the implants can move around within the packaging risking damage to coatings. U.S. Pat. No. 3,013,656 discloses the use of blister packs, with an additional support layer of cardboard behind the first layer to package surgical instruments to ensure the instruments are sterile when delivered to a surgeon. The first layer comprises a flexible plastic layer for instance polystyrene or vinyl and defines recesses to receive breakable articles. Some of the recesses have mouths which are narrower than the maximum width of the instruments to be received. The mouths deform when the instrument is inserted or removed to securely hold the instrument in position.
U.S. Pat. No. 4,697,703 discloses a blister pack for holding a medical item, such as a surgical implant. An inner package is received within an outer package each of which is sealed with a film cover to provide two sterile barriers. The inner package further includes a lid and a pair of shaped inserts to fit within the inner package. The inserts define projections which extend into the centre of the inner package to cradle the medical item such that the medical item is not free to move within the inner package.
It is an object of embodiments of the present invention to obviate or mitigate one or more of the problems associated with the prior art, whether identified herein or elsewhere.